<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8"></meta>
    <title>hello</title>
</head>
<style type="text/css">
    body {
        padding: 10px
    }
</style>
<body>

<div>
    <!-- 后面添加参数起到清除缓存作用 -->
    <img alt="验证码" onclick="this.src='/defaultKaptcha?time='+new Date()*1" src="/defaultKaptcha" />
</div>
<form action="/imgvrifyDefaultKaptcha" method="post">
    <input type="text" name="tryCode" />
    <input type="submit" value="提交" class="btn btn-success"></input>
</form>
</body>
</html>
